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Anathema: The complete Shadow Priest guide. v1.3

Post by Sinespe

Table of Contents:

Post 1: Introduction: Outlines of goals when ... Levelling, PvE, PvP; Abbreviation Key.
Post 2: Levelling: Your Spells, and What They Do; Talent builds; Itemisation.
Post 3: PvE: Talent Builds; Spell Rotation (Trash/Bosses)
Post 4: PvE Continued: Itemisation -- Simcraft, Pseudo-Power and You. == UNDER CONSTRUCTION ==
Post 5: PvP: Your Spells and Glyphs
Post 6: Your Role (Battlegrounds); Battleground specs
Post 7: Your Role (Arena); Arena specs; Arena partners.
Post 8: PvP Gear: Priorities; Arena Sets; Notable Gear; Gems.
Posts 9-14: PvE, The Revenge: Advanced Tactics on Bosses, Specific to Maximising Your Role as a Shadow Priest. Naxxramas, Ulduar, Trial of the (Grand) Crusader and Icecrown Citadel, wing 1.
Post 15: The Archivum

Introduction

Greetings, and welcome to the Shadow Side of Sacred Slaughter. This guide intends to give you all the information you could find useful on the subject of playing a Shadow Priest in any capacity. Whether you want to melt bosses' faces, make that pesky Rogue jump off a cliff, or you just want some variety while you're levelling, this guide will show you down the dark, deadly Yang to Holy's Yin.

The Shadow tree of the Priest class focuses in dealing damage. We are, therefore, a Hybrid in which two trees focus on healing (In vastly different ways), and the third on DPS.

Why Level Shadow?

The better question is: When? Shadow Levelling comes into a world of its own beyond Level 50, at which point you gain an added DoT in the form of Vampiric Touch. All of a sudden, you have increased longevity and DPS -- suddenly you drink every 6 mobs, rather than every 2. Before level 50, you can still level Shadow, if you wish. However, the benefits are questionable, especially below Level 44, where Mind Flay suddenly catches up to the level of DPS required to compete efficiently with the health scaling of the mobs you are fighting. Below the aforementioned fourth rank of Mind Flay, you might consider Holy/Discipline levelling, as I outline in the excellent General Priest FAQ, or as Chiv outlines in his Energizer guide. They are slightly different in their advice up to level 50, but they aim at the same goal.

Mind Flay's animation specifically hits the face now? Awesome! Time to give Yogg-Saron a face..."lift"...

In PvE, Shadow Priests do excellent Trash DPS with what is designed to be the most powerful AoE in the game -- Mind Sear. On bosses, they have niche utility that sets them apart from other casters, while still remaining competitive on DPS apart from at the very upper echelons of present raiding content.
Misery, similar to a Boomkin's Improved Faerie Fire, is a buff around which all casting raiders base their hitcap gearing ideals -- 3% is roughly equal to 78 Hit Rating.
Replenishment, provided by a Shadow Priest through a combination of Vampiric Touch and Mind Blast, is vital for raiding, as Blizzard tunes encounters on the basis that it is available, to the point where Tank analogies are made. Although other classes have this ability, it is only in the case of Shadow Priests and Retribution Paladins where you are guaranteed that the DPS will come with Replenishment. In the case of Hunters, Mages and Warlocks, the Replenishment talent is in one third of a DPS-focused set of talent trees; but for Shadow Priests and Ret Paladins, it comes with the whole Face Melting/Righteous Destruction package.

Stunlocked? Try stunning a ball of gas, Rogue Boy ... You call that an eviscerate?

Shadow Priests have a split usage in PvP. In Battlegrounds, you can generally go to town Mana Burning people, Dotting up everyone, focus-firing a single target into oblivion, or Mind Controlling people off of Lumber Mill in AB. In Arenas, your role is more focused on doing insane Burst damage or being part of a Mana draining team (The former is generally more popular than the latter). It is a testament to our deadliness that we are focus-fired as a first priority. We are a glass cannon of brutal power, whether healing as Discipline or DPSing as Shadow, and we are very dispel-resistant, with talents such as Silent Resolve to outright prevent such dispels, and Shadow Affinity to make dispels less of an issue.

Common Abbreviations

Post by Sinespe

Levelling as a Shadow Priest

Your spells, and what they do

Level 1: Smite -- You will only use this spell for the first few levels, most likely, because once it becomes a 2.5-second cast (Since it won't be talented) it will be more of a burden than anything else.
Level 4: Shadow Word: Pain -- Though this is a Bread and Butter spell at level 80, it is not necessarily so for levelling. It is quite an expensive spell (in terms of mana cost), and probably won't tick to its full duration because the mob will likely die before such a time. It is, therefore, player choice whether the extra damage is worth it.
Level 10: Mind Blast -- A standard nuke spell. 8 second cooldown can be talented as low as 5.5 seconds, but this isn't so necessary for levelling, since it should only be cast once per fight, twice if the user feels like it.
Level 20:

Devouring Plague -- Use only on hard-to-kill mobs. Very expensive, but good damage: not something to be used in standard levelling rotations.
Holy Fire -- Until you get Shadowform, this is a very useful opening spell, with high damage.
Mind Flay -- The bread and butter of levelling, but very weak at such a low level. Spammable due to a low mana cost.
Shackle Undead -- A situational CC, but useful in some zones. It can even be used to solo certain Elites.

Level 40: Shadowform -- At this point, stop casting Holy spells, because you'll be pulled out of form.
Level 50: Vampiric Touch -- The Shadow Grail of levelling, longevity, and DPS. Powerful DoT, proccing Replenishment to prolong your mana pool between drinks.
Level 60: Dispersion -- Another excellent longevity talent, which also provides survivability if you get into trouble while levelling or PvPing.
Level 62: Shadow Word: Death -- A useful spell in some circumstances. I use it often because I'm impatient about waiting for that fatal DoT tick to kill the mob. Not essential for levelling, though.
Level 66: Shadowfiend -- Yet another way to increase the length and sustainability of your ... mana bar.
Level 75: Mind Sear -- An important note about your beloved AoE: Don't use it to AoE farm. It isn't very efficient. It's more efficient and in general actually quicker to DoT up a mob with both VT and SW: P, then massacre it with a Mind Blast and a couple of Mind Flays, than it is to round up lots of mobs and cast Mind Sear while suffering a fair amount of pushback.

Talent Builds

The talent build before level 50 is perhaps mis-informed, since my most recent priest only levelled Shadow from 50 upwards. However, it is based on my experience and is, hopefully, accurate: Taking everything that will speed up levelling, and ignoring a lot of the unnecessary stuff until it's useful to get it. The progression fills out into my preferred PvE level 80 talent build (There are two). This section is mainly ripped from my guide on levelling in the FAQ. It is split into two sections, giving slightly different choices: A "PvE Realm" build, and a "PvP Realm" build. If you care about being ganked, and want to put up the best fight possible when someone decides to have a go, then go with the PvP Realm route.

A note on wands: Wanding, which used to be "The" way to level, has become slightly less potent since the removal of Wand Specialisation; however, it is still useful to have the highest-level Enchanter-made wand for your level until about level 35, where wand damage gets outclassed by the amount of HP that mobs have.

A brief note, also, that square brackets PvE Realm:

10-39 -- Rotation: Holy Fire (Smite until you get Holy Fire), , MB, MF, MF, Wand.

40-49 -- Rotation: MB, , MF to death, with additional Mind Blasts if you want to.
As you see, DvPl has been ignored for now, because, apart from difficult mobs, it shouldn't be used. The points are better spent in Darkness, Mind Blast and the like. Additionally, a point in Improved Fade comes into play, because, as you'll see later, by the time you get the Shadowfiend there are no more points to spend in Shadow for a long time; so getting the talent in advance is a good idea.

50-60 -- Rotation: VT, , MB, MF, MF, etc.
At this point, you have plenty of mana regeneration and you can usually kill 5 or 6 mobs, one after another, before having to think about drinking -- and when you get 60 you have Dispersion for even more mana. 5 or 6 mobs between drinks might not sound like much, but, before you get VT, it's pretty dire. After 60, no more points in Shadow should be invested, since you can now go into Discipline to get Meditation as soon as possible. This will not only maximise your mana regeneration at the earliest possible juncture, but ensure that you can more efficiently heal in Northrend instances, sooner, even if you stay Shadow specced.

61-73

74-80

PvP Realm:

10-39

40-50

51-60

61-73

74-80

Itemisation for levelling

As stated above, keep your wand up to date with the latest Enchanting-crafted wand, unless you can get a better one through questing. Aside from that, focus on a balance of Intellect, Spirit and Stamina, picking up pieces of gear with Spellpower or Crit where you can find them. Spirit-stacking is no longer very useful since Spirit regeneration mechanics were changed, reducing the overall potency of Spirit Tap.

As soon as you max out Shadow Power, Crit becomes a lot more useful for levelling than Intellect or Spirit. Getting regular crits on Mind Flay, especially if you are going with the strategy of VT --> MB --> MF to death, makes killing things a lot faster and easier. For this, you need around 10-15% unbuffed; Mind Melt provides the rest.

Post by Sinespe

PvE: Melting Bosses' Faces and You

Talent Builds

In the history of the Shadow Priest, there has always been a definitive "Cookie cutter" PvE spec. In 3.1, however, this has changed very slightly.
PvE Shadow Build

For the first time, there is a Shadow PvE build which relies on players' own judgements of what is useful and what is not. In this build there is flexibility: five points are left blank.

The problem is one of usefulness. There are five points for four talents: Inner Focus, 3/3 Spirit Tap & 2/2 Improved Spirit Tap, 3/3 Shadow Affinity, or 2/2 Improved Vampiric Embrace. But, there isn't really much competition here.
Improved Spirit Tap does not provide much of a DPS boost. It has been increased recently to proc off Mind Flay crits along with Mind Blast crits, which give it an uptime approaching 100%. However, increasing your spirit by 10% merely means that you increase your overall Spellpower benefit from Spirit by 5% (10% of 50% from Glyph and Talent). In practical terms, this turns Spirit from a 0.52 PP stat to a 0.57 PP stat. The boost is very, very insignificant for five whole talent points, when the other options provide much more utility.

So, we discredit 2/2 IST altogether, since it is very, very lacklustre. If it increased your spellpower by 10% of your spirit, similar to how Twisted Faith and Glyph of Shadow work, then it would still be, marginally, worth taking.

3/3 Shadow Affinity means you will avoid aggro pulling 99% of the time, even if you put your DoTs up on a target which has only just had its attention caught by a tank. This doesn't sound like it's very much use, but on some fights you're going to have a damage boost which isn't given to the tank -- that means your TPS approaches tank-generation levels unless you have as much threat reduction as you can get your hands on. Overall, it is a DPS increase, because it means you never have to worry about slowing down for fear of pulling aggro.

Inner Focus vs Imp. VE is player choice. Inner Focus is a minor DPS boost; 2/2 Imp. VE is a pretty major boost to your healer-buffer capacity. Imp VE is also one fewer button to push, of course.

Spell Rotation

Trash Mobs

On Trash Mobs, the idea is simple:
1-3 mobs: VT and SW: P two or three; Devouring Plague one of them, do boss rotation (See below)
4+ Mobs: VT and SW: P one target; on that target, Mind Sear.

Bosses

On Bosses, rather than having a set rotation, you have a list of priorities to follow.
1. VT and DP must be kept up as close to 100% of the time as possible.
2. MB must be cast whenever it comes off cooldown
3. Mind Flay must be cast if neither DoT requires refreshing and if Mind Blast is on cooldown.

Shadow Word: Death does not fit into this list of priorities, per se. It is a filler, and should be used only if there is a GCD-length before needing to refresh a DoT or cast Mind Blast.

Shadow Word: Pain, too, does not fit into this list of priorities, because there is a specific time that it should be cast. The talent Pain and Suffering will refresh Shadow Word: Pain, and will update it to deal the correct amount of damage based off your current spellpower number on the character sheet. However, it will not update with any other effects which may improve its damage. For instance, if you cast SW: P when you have one stack of Shadow Weaving active, and you then cast Mind Flay after you've built up four stacks, SW: P will not be updated to 8% extra damage; it will still be on 2%. You must, then, cast SW: P only once you have five stacks of Shadow Weaving. You, therefore, have an opening rotation, to get five stacks of Shadow Weaving as quickly as possible:

VT > MB > MF (Make sure all three ticks go off; each tick gives one stack of Shadow Weaving) > SW: P > DP > MB.

The following list gives an indication of when you should hard refresh (I.e., press the button itself again) SW: P:

Things not refreshed by Pain and Suffering:

Crit percentage number listed on Character Sheet (Exam ples)
Shadow Weaving stacks
Crit percentage chance on boss effects (Example)
Flat damage-percentage buffs or debuffs on yourself (Example)

Itemisation Theory and Practice

Some basic facts before we start getting into item scales and whatnot:
To remove your chance to miss against a level 82 mob (Heroic bosses, for instance), you need 6% added chance to hit, across your gear, talents and racials.
To remove your chance to miss against a level 83 mob (A raid boss), you need 17% added chance to hit, across your gear, talents and racials.

You need 0% added hit chance from gear to do Heroics. All of your requirement is met by Shadow Focus and Misery
You, therefore, need 11% of hit chance from gear to be hit capped against a level 83 boss.
1% of spell hit from gear is 26.232 Hit Rating. Therefore, 11% of hit is equal to 288.5 hit rating, rounded to 289.
If you are a Draenei, or you are guaranteed to have one in your group for your raids, then your required hit rating drops to 262.3, rounded to 263 -- 10%.

Post by Sinespe

== UNDER CONSTRUCTION. ZUG ZUG. ==
Itemisation
"What stats do I want to stack as a Shadow Priest?"

Let me introduce you to my friend called Simcraft. Simcraft is a tool that people can use to simulate boss fights -- mostly "Patchwerk" style: stand and nuke from 100% to dead. It generates a readout of a gear set's potential maximum DPS threshold, which is calculated by running this "Patchwerk"-style encounter up to 10,000 times. It can also be used to generate weight scales. These scales are generated by varying, by 1 point at a time, up to 200 points above and below your current value of a given stat and running a simulation with that adjustment, to see what effect it has on your average maximum DPS.

Weight scales are very fragile. By changing a gear set to include an item which has exactly the same stats as another item, but with all its Haste substituted for Crit, you will cause the weight scales you receive to be altered. Expanding this idea further, if you are in a particular set of Tier gear with set bonuses, these set bonuses can cause the relative value of all your stats to go up or down depending on what the bonuses do. Thus, and this is very important, there is no overall weight scale which can be followed from Quest Greens to Tier 10.277 gear.

That being said, however, some overall aspects of the Shadow Priest class, such as spellpower coefficients and relative damage percentages, do not change quite so much. For instance, Mind Flay will always be, under normal single-target circumstances, roughly 30-40% of your total damage done. As a result, if one doesn't take into account set bonuses which alter our rotation dramatically, such as the Tier 8 and Tier 10 four-piece set bonuses do, then one can see similarities between gear sets that have their stats increased roughly proportional to each other.

Therefore, rather than feed you a gear list or an over-arching single PP value for BiS/non-BiS gear levels, as Shadowpriest.com tends to do, I will instead set up several different gearing profiles to show various stages of progression up to ICC-ready gear and show you how the PP values of each stat interact with each other as all stats are increased.

Oh, a brief explanation of PP. PP is an abbreviation of "Pseudo spellPower". When weight scales are generated, their rough forms are shown as "Increasing Stat X by 1 point will give a Y.Z DPS increase". PP is just those same figures normalised with respect to Spellpower -- i.e., "Spellpower" is always brought to "1", and all other stats are made proportional to that normalised value.

The following assumptions are made for all simulations: All raid buffs are present, and the fight is 5 minutes (300 seconds) long. "Player Skill" is set to "elite". The spec used by each profile is shown -- it's the one I use: here. You are assumed to be Flasked, Food Buffed and use one Potion of Speed during the test. Heroic Presence is not assumed.

Gear list the First: Just-dinged level 80.

Grats! You've made it to level 80. Your gear won't look exactly like this, but the stats will look similar. You're under the hit cap, your stats are low. Let's see what Simcraft makes of you:

Spellpower: 1 PP
Hit Rating: 1.04 PP
Crit Rating: 0.48 PP
Haste Rating: 0.47 PP
Intellect: 0.19 PP
Spirit: 0.58 PP

The first thing to do, of course, is to get Hit-capped. While you're below the hit-cap, you're artificially decreasing the value of Crit, since any spell which doesn't hit doesn't even roll to crit. It should be noted that Spirit is pretty much as much of a barometer as Spellpower is in terms of PP: Since it gives a direct spellpower conversion, the only factor which can increase or decrease it is its uptime. At such a low value of crit, it is already at 95% uptime.

Gear list the Second: Hit-capped and Normal Instance Running.

Not only are you now hitcapped for raids, but you've even been busy getting some Normal 5-man upgrades. Given the potency of Normal rewards from ToC5 and the three ICC 5-mans, normal instances are worth the effort you put into them.

Spellpower: 1 PP
Hit Rating: 1.03 PP (0 at Cap)
Crit Rating: 0.58 PP
Haste Rating: 0.64 PP
Intellect: 0.18 PP
Spirit: 0.54 PP

See that the values of Haste and Crit rise proportionally to each other. Haste is slightly more pressing on the agenda for further gear development because the profile itself has 481 crit rating to 365 haste rating.

Gear list the Third: Hit-capped, Heroic Instance farming

You've now farmed quite a few Emblems of Triumph and built up a decent gear set. This one is capable of pulling 6.5k DPS on Patchwerk (so, in practice, about 5.8k, accounting for human error). A skilled Shadow Priest would be able to clear the Icecrown DPS thresholds with this gear. Crit and Haste have become slightly further apart in this gear set, and that's reflected in the change to PP:

Spellpower: 1 PP
Hit Rating: 0.71 PP
Crit Rating: 0.64 PP
Haste Rating: 0.74 PP
Intellect: 0.19 PP
Spirit: 0.53 PP

Gear list the Fourth: ToC10 Farmer. ICC Ready

Unless your realm is filled with PuG leaders who foam at the mouth when they see any gear under iLvl245, this kind of gear will get you into Icecrown Citadel without any questions. It's important to note here that, while Haste overtakes Crit in terms of balance, it nevertheless comes out above Crit in terms of PP. This is helped by the four-piece set bonus -- If Mind Flay is critting more often, it becomes more beneficial to make those crits happen in a shorter space of time than it does to increase the crit chance even further. Without the set bonus, Crit is worth a tad more at 0.69 PP, but haste is largely unchanged except by fractions of fractions of PP.

Spellpower: 1 PP
Hit Rating: 1.15 PP
Crit Rating: 0.67 PP
Haste Rating: 0.80 PP
Intellect: 0.20 PP
Spirit: 0.54 PP

So, as you see, increasing all stats proportional to each other is important, and those proportions can be seen through Simcraft for your particular set of gear. It's also important to understand why Crit, for example, does not rise quite so quickly as stats such as Haste. Aside from set bonus reasons, crit suffers from a diminishing return. What that means is best demonstrated thus:
Let's say you have a 20% crit chance. If you were to increase this chance by 1%, you would have given yourself a 5% increase in crit chance: 21 / 20 = 1.05
Now let's say you have 40% crit. Increasing it by 1% gives a mere 2.5% increase in crit chance: 41 / 40 = 1.025. You're gaining the same amount of Crit, but, because your crit is already so high, linear additions of crit add relatively less and less respective crit chance.

Haste does not suffer this problem, especially since 3.3, because all Haste does is increase the speed with which we can cast spells and the speed at which our DoTs tick. It is linear and, except at certain very high levels when you become GCD-capped under the effect of Heroism/Bloodlust, it will give a linear benefit.

Gems

Meta: Chaotic Skyflare Diamond. There is no substitute for this.

Red: Runed gems are your choice for a red socket, unless Haste is equal to or better than Spellpower, in which case go with ...

Yellow: Reckless. Given the consistency that Haste has been given in 3.3, and the aforementioned reduction of diminishing returns, Reckless will provide more mileage at all gear levels than Potent.

Blue: Purified. You need at least two of these to activate your Meta gem. However, they are also very strong in blue +Spell Power socket bonuses. Given the predictability of Spirit, always hovering around the 0.5 mark, they're worth at least 15 PP without any socket bonus. If you wish to be OCD, you can be in 3.3 without losing much more than mere single points of Spell Power here and there.

Post by Sinespe

PvP: Would you be interested in double-glazing?
Make people gasp, "Oh my" at your survivability!

Oh god, What do I do what do I do what do I do?

In order to assess your role in BGs and Arenas, let's have a look at your PvP-oriented spells:

Shadow

Your shadow spells revolve around a mixture of Control and Survivability, with burst ability being provided by the nature of your rotation, which will be explained slightly further on.

Silence: What's more to say than what's on the tooltip? Neuters a spellcaster for 5 seconds, plus however long into their cast they were before you activated it on them.
Psychic Scream: Your standard "Get away from me" button -- this is the skill which most people will blow their trinkets to break, because eight seconds is a very long time in PvP. It stops scaling after affecting five players because that's the maximum you'll get in an arena match.
Psychic Horror: A gorgeous PvP talent in the 3.1 Patch, neutering a Melee DPS for anywhere between 5 and 13 seconds, depending on his choice of trinket usage and disarm-reducing talents or enchants; and causing another three seconds of irritation to a spellcaster.
Dispersion: As mentioned in the PvE guide, this is an excellent survival talent. Some argue that the loss of the ability to cast spells for 6 seconds makes it less useful, and that the loss of the healing component (present in beta for a short time) makes it even less potent. However, the removal and immunity to snares is not at all something at which to sniff.
Improved Shadowform & Fade: Chiefly, this should be used to remove things like Hamstring and Crippling Poison, which are the two chief offenders of a Shadow Priest's escape. Remember that Judgement of Justice will not be removed by this ability.
Mind Flay: Exercise caution when using this spell. It does very nice DPS, and the snare component is superb, but be aware that it is the most obvious indicator to all your enemies of precisely where you are standing. If you're trying not to be seen, do not use this spell.
Mind Control: Mainly a Battleground talent, but a very fun one. use it to throw people to their deaths.

Discipline

Mana Burn: Only use this if you've talented to reduce it to 2 seconds, and only use it on high-mana-pool targets, since it was changed to scale to mana pool, rather than burning a flat amount of mana, thus preventing Enhancement Shaman and Retribution Paladins being neutered in two casts.
Dispel Magic: An insanely useful spell. Twice as effective as a Cleanse or a Purge for magic debuffs, and acts as both. Chiefly, as a Shadow Priest, you'll be using the purge component of this. Whatever you do, don't forget that you have it. It's a wonderful little ability.
Mass Dispel: This pops bubbles and melts ice. Be aware that it has a lower chance to hit, especially against Paladins with their added Dispel protection talent, Stoicism, so be prepared to cast it twice if necessary.

Holy

Yes, indeed, Holy spells. Sometimes, you really should drop form and heal. If your timing is good, it could be the best 1.4k mana that you ever spend.
Prayer of Mending: Some Warlock being a bit trigger-happy with his DoTs and applying them to multiple people? Slap this baby on and watch it bounce around at lightning speed.
Binding Heal: This spell is unique. Beacon of Light comes close to emulating it, as does Chain Heal, but nothing is so effective as this at what it is designed to do. You and your partner both need a flash heal? Use this! Brutally effective at mitigating split damage in a 2v2.

PvP Glyphs
PvP glyphs are not as rigidly set as they are in PvE, since there is more scope for personal preference, even in Arenas. Therefore, I will list potential glyphs and say why they are useful.

Shadow

Major
Dispersion -- Simple enough choice. 45 seconds until your "No death for me!" button comes back. A solid choice
Fade -- Reduces the time on your snare-removal ability. Uncommon, but it can be useful if you want it for a specific purpose
Psychic Scream -- Useful in one situation, and one situation only; but nevertheless worth mentioning. In Arenas, this will most likely be trinketed, so it's not worth it. However, in Battlegrounds, particularly AV and AB, this is incredibly useful as it brings your Psychic Scream duration to the precise amount of time required to capture a base, just in case the random movement doesn't take them far enough away.
Shadow Word: Death -- More burst is good, but beware of the backlash should the target not snuff it
Shadow Word: Pain -- More damage on Mind Flay. Useful if you're in a situation which doesn't call for subtlety

Minor
Fading -- Less mana cost = slightly more longevity
Shadowfiend -- The shadowfiend is now less resilient to damage, since its 75% resistance to everything has been replaced with an excellent health-scaling mechanic. As a result, it dies easier if it's focused.

Discipline

Major
Dispel Magic -- Speaks for itself. Useful if you dispel a lot of debuffs
Fear Ward -- Effectively just "Reduces the cooldown on Fear Ward". A nice glyph to have to reduce the amount of CC you suffer.
Inner Fire -- More armour = Stay alive longer.
Mass Dispel -- If you find yourself using this spell a lot, take this glyph. However, it's not much of a priority.
Power Word: Shield -- A solid glyph choice if you like to shield yourself a fair bit.

Minor
Levitate -- Express Jesus-bomb incoming to Blacksmith from Lumber Mill! Cost? Nothing at all!
Shackle Undead -- Very useful against ghouls and Lichbourne Death Knights.

So, these are the weapons at your disposal; how should you use them?

Post by Sinespe

Battlegrounds

In Battlegrounds, don't take things too seriously. There is absolutely no point in getting bent out of shape over something that you have to do regularly to get good Non-set PvP gear. Mix things up. Don't stick to doing what you do in Arena, unless you're with your arena partner(s) at the time. For some ideas of what you can do, here's a breakdown of battlegrounds:

Warsong Gulch: With Dispersion being what it is, you are a very strong candidate for flag-running. Six seconds of no snares, plus a Fade for even more running time, could lead your team to victory. Don't be afraid to pick up the flag, even with that warrior there! Just Dispersion, get the speed buff, and watch him disappear into the mists as you charge down the field.

Or, if that doesn't float your boat, or they're turtling too much, play your Glass Cannon card to its maximum ability: Find a Berserking buff and DOT. UP. EVERYTHING. Let yourself die when you get into trouble, and watch the delicious numbers pop up halfway across the battlefield as you sit at your graveyard and wait for the res. Remember, don't use Mind Flay while you're doing this, as you want to remain as discreet as possible for as long as possible, casting VT and SW: P on anything that moves.

Arathi Basin: Mind Control off Lumber Mill and down from the Western path of Blacksmith to Gold Mine. Laugh as you sneak up on unsuspecting opponents, deep in a mêlée with members of your team, and uninterruptedly take control of their bodies and end the fight suddenly. Remember, don't pull them outside of 25 yards, or it will break from the strain on the range of the spell.

Eye of the Storm: Again, Mind Controlling off bridges is fun.

Alterac Valley: My favourite thing to do here is to defend the rearmost towers/bunkers of your team. You can DoT people before they enter, and they may not even enter (Again, be discreet, so no mind flay!). With your survivability, you can hold your own for an extremely long time and call for assistance. Causing an enemy to burn their trinket can also result in an easy re-capture of a lost tower, because Psychic Scream will do all the work for you.

Strand of the Ancients: I've never actually played this battleground, so I don't actually know if there's anything unique that a Priest can do to amuse themselves! Answers on a post(card)!
Zerul and Aldones have shared theories. Additional information is still more than welcome!

Battleground Builds

Because there are so many things you could be doing in Battlegrounds, and emphasis is going to be slightly less on professionalism and targetting (At least in the case of Pugged BGs), your build can be a little relaxed, if you prefer. I present, then, leisurely builds in the Battleground section. Arena junkies should skip right on ahead to the Arena section, where there are builds which are Arena-dominant; and, therefore, naturally serviceable in Battlegrounds, too. As these are quite leisurely, feel free to experiment and make your own combinations of talents and glyphs!

14/0/57, Your resistance is insignificant! This build works off the premise that pugging in Battlegrounds is just asking for lack of dispels. It takes no dispel protection, and wholly focuses on obliterating opponents with as much efficiency as possible, and keeps you going for quite a while with Meditation if you choose to focus on single-target facemelting rather than dotting up a mass of enemies.

20/0/51, You not kill next one so easy! A build entirely focused around escaping from danger. 9 seconds off Fade is a huge reduction in the time spent waiting before you're next able to remove snares; and reducing Dispersion's cooldown by 45 seconds is vital for flag running again, and again, and again.

19/0/52, Burn, you hellish mana! A spec containing Mana Burn.

Post by Sinespe

Arena

Your role in arena takes two forms. On the one hand, you have your burst/control capability. Combine yourself with another class, also with its own set of CC and burst abilities, and you have a lethal combination which can incapacitate the healer of a Healer/DPS combination for up to 50 seconds, and destroy their partner with ease. On the other hand, you have Mana Burn. Generally, this is more of a 3v3 and 5v5 idea, as Mana Drain teams work best in larger groups.

Burst: Cast VT followed by SW: P. Now cast Mind Blast and immediately hit SW: D. All four of your effects will tick and land at the same time, causing a ridiculous level of burst damage as your victim also suffers an assault by your partner(s).

Be clear with your partner(s) about CC rotations and targets, so that your timing is immaculate, and make sure you are ready to tackle any Bubbles or any counter-CCs. SW: D out of Sheep (requires good timing to pull off) if you see it being cast on you, and then trinket the 5-second duration version (Mages will always Poly you because you are the dispeller). Keep an eye on buffs and debuffs on your opponents and yourselves -- be prompt to counter magic debuffs, but keep an eye out for Unstable Affliction, for instance.

Mana Drain: DoT up targets to force enemies to dispel, and cause as much damage as you can between Mana Burning the hell out of the healer. Even if you just force a form-change in a Resto Druid, that will stop him healing for a time. Dispel all HoTs as quickly as possible to force re-application. Again, use your CCs well and cleverly.

Arena Builds

There is some debate over the usefulness of Shadow Power. It does provide more burst; but, since it affects the damage of Shadow Word: Death, it can do more harm than good. Therefore, there are alternative builds listed in the "Burst" category for the kind of output you feel you need to do.

20/0/51, This pathetic siege ends NOW! This build includes Shadow Power, and includes Meditation rather than going for Improved Power Word: Shield for more sustained nuking. It will deliver as much Burst as you can muster, so be careful about your survivability!

20/0/51, Slowly, slowly, killy Roguey. This is a build excluding Shadow Power. More emphasis is on survivability, as can be seen in the Major Glyph alteration. Nevertheless, this build should provide enough DPS to kill a class before you run OOM, so mana conservation talents, for the most part, are not desired.

20/0/51, The Slow Burn. A mana drain build. A mix of survivability and irritation. Every time you are dispelled, which must occur, you gain mana back so that you may just re-apply the DoTs, and all the while your enemy's mana bars are dropping.

Arena Partners

Burst/CC:
Rogue: The cookie-cutter, beautiful combination. A deadly mix of heavy burst damage and a wide range of CCs
Unholy Death Knight: With 30% increased disease damage and 13% extra spell damage on your victims, your DvPl will deal more damage and heal you for more, and spellcasters will be powerless to cause you any decent amount of harm.
Arcane Mage: An uncommon pairing, and I'm not sure of the utility, but in theory it should work quite well, since Arcane Mages have high burst and excellent kiting/CC abilities.
Beast Mastery Hunter: Excellent burst, and can even mana drain while CCing, kiting, and Big Red Kittying.
Affliction Warlock: A brutal pairing. Less CC than most, so not so much survivability, but a dire combination of DoTs. Make sure pesky melee classes stay off your partner long enough for him to get UA off, and your enemies will die, slowly but surely.

Mana Drain
Hunters for Viper Sting, annoying kite healers such as Resto druids -- the concept is versatile to accommodate many different specs.

Post by Sinespe

PvP Gear

First, let's look at your priorities when gearing:

Resilience
You need 82 Resilience Rating for 1% of Resilience at level 80. A good starting point for Resilience is 900, about 11%, which gives a good base of damage mitigation
Stamina
A somewhat weaker stat than Resilience, but still necessary. No use being hard to kill in terms of Resilience if you don't have the healthpool to back it up. In general, though, the stamina that you get from the white stats on PvP gear should suffice.
Hit Rating
4% is required on same-level targets. However, some racials provide additional miss barriers. To out-hit this, you need 158 Hit Rating, 6%. It is very important that this is on your gear, not merely through your talents, for two reasons.

Shadow Focus only affects your shadow spells, not Dispel and Mass Dispel.
Misery will not always be on targets, so you can't rely on it 100% of the time for Psychic Scream or Mass Dispel.

Removing as many RNG elements as possible is a very important part of PvP.
Spell Penetration
130 is the target here: One point of spell penetration will ignore one point of resistance, and 130 is the maximum that a player can buff themselves with, outside of a Paladin using their Aura Mastery ability, which is unlikely to happen while using Shadow Res Aura, or someone gemming for resistance, which is a pretty stupid idea.

Arena Sets

The Shadow-oriented PvP set is Satin, with Mooncloth being spirit-oriented. Both have the same set bonuses:

(2) Set: +50 Resilience Rating.
(4) Set: Reduces the duration of the Weakened Soul effect caused by your Power Word: Shield by 2 sec.

In Shadow PvP, although you will use your PW: S, it's very unlikely you will use it every 13 seconds, or even every 15 seconds, so the (4) set bonus isn't as good for you as getting the (2) sets of both Mooncloth and Satin. I will not suggest, though, which combinations would be best (I.e., which items of Mooncloth and which of Satin to take). The socket bonuses are much different, even if the only difference between item point distribution is in transferring Crit and Spirit.

Noteworthy gear

Look out for the Titan-forged items and the ~~Focus Staves~~ (NB: Blizzard removes old weapons as the new season comes out, so you'll only have access to the weapon of the latest season) when trying to get your hit rating up to the required level. Regarding non-set PvP epics, use whatever you feel will benefit you. Haste is quite nice if you don't want to rely too much on the RNG-heavy Crit. There is also Hit to push up that rating.

Gems

There are many Meta gem options besides the obvious, depending on what you want.
Chaotic Skyflare Diamond: The old, faithful PvE gem remains the same. It gives an additional burst capacity for an offensive strategy.
Efflugent Skyflare Diamond: A boatload of stamina and a reduction of magical damage. Not the most useful, relatively speaking, but nice nevertheless.
Forlorn Skyflare Diamond: Reduced Silence duration can be a powerful anti-lockdown tool.
Insightful Earthsiege Diamond: This one is a potential choice for the mana burners, giving an increase in mana pool.
Tireless Skyflare Diamond: I mention this as a choice for Engineers only. You should have Enchant Boots - Tuskarr's Vitality for your movement speed increase. If you are an Engineer, though, this is an alternative, since you should have Nitro boosts on your boots.
Trenchant Earthsiege Diamond: A powerful anti-lockout choice. This reduces stuns multiplicatively with your Talent, making you even more of a nightmare for Rogues.

These following gems are potent choices offering Resilience and offensive/defensive stats:
Durable Monarch Topaz
Steady Forest Emerald

Then, of course, you have old favourites:
Mystic Autumn's Glow
Runed Scarlet Ruby
Rigid Autumn's Glow
Veiled Monarch Topaz

This section is quite short because there's not a lot else to say. Again, I don't want to fill up space with needless gear lists, so I have given gemming advice and stat priorities. If anyone has any questions or additions to this section, feel free to leave a post.